No, this isn’t me, I found this video on You-Tube and had to share it with everybody on Lumberjocks. I’m sure this was only done for fun, and don’t try this at home, but I don’t see why it wouldn’t work if you made some slightly better big lathe tools.

About 20 some years ago there was an article on Old House Journal where a carpenter had to turn some large column bases and he used his van back axle. He fabricated a large stationary tool rest, don’t remember how, think it was driven into the ground. I think he bought a junk steel wheel and drilled some extra holes in it to use as a baseplate. It worked out well for him.

That last pic just looks like a serious accident waiting to happen. Only major issue I can see, provided it is all bolted tight, is that the wheel bearings might not be adjusted tight enough leading to bad runout. Although it can handle the load and probably idles around 700rpm. Better would be to mount the engine to an external frame and bolt to a modified flexplate. As long as there is a radiator hooked up and a fan it would run all day if you provided the fuel.